Namespace Util

    Public Class StringUtil


        Public Function is_number(ByVal var As String) As Boolean
            Dim i As Integer
            If Len(var) = 0 Then Return False
            For i = 0 To Len(var) - 1
                If Asc(var.Chars(i)) < 48 Or Asc(var.Chars(i)) > 57 Then
                    Return False
                    Exit Function
                End If
            Next
            Return True
        End Function

        
    End Class

End Namespace